@TrueGoddessReincarnation: Difficult to say. They are still publishing the chapters, so it might have been the case, that the editors might have told him to go into that direction, but I think otherwise.
In regards of the health tips: Maybe they got shot down by some reader reactions, who might have criticized them harshly. To be fair, if you just slap in such a tip into the story and it takes up too much panels in a chapter, it does feel forced. I really liked the quickies though.
And in regards to the girl weights... I do believe it takes actually some more effort to draw the extra curves (jelly rolls), than to just draw some lean bodylines, even when you throw in some tuned down athletic muscles here and there. So it isn't a case of laziness, but maybe he is trying to convert as many readers as possible to his personal preferences? So, maybe he gave up in regards of providing diversity and gave in to his own desires. That's what I believe, that happened.
It's just a tad bit sad. As there is no real storyline (Erufuda isn't even trying to diet anymore, for example), only slice of life, that goes nowhere, an overgrown harem (member count wise, not sizes-wise. At least they haven't all fallen madly in love with MC) and the girls ain't fitting my target range anymore, I'm getting less and less thrilled about a new chapter. I know "Big is beautiful", but this only applies to girls, whose charms work with it. In this case, it is less about charm and it feels more like "Look at those tits, arses and fat rolls!" I got hooked by chapter 1 and stayed so far because of chapter 2.